Systems for manufacturing tobacco products will generally comprise a plurality of machines linked one to another along a common production line. In particular, such machines will include a cigarette maker at the upstream end of the line and, arranged in succession proceeding toward the downstream end, a filter tip attachment, a packer, a cellophaner, a cartoner and finally a machine by which pluralities of cartons are parcelled into boxes of whatever type, ready for despatch. Where large boxes are used, the despatch area will be equipped with an end-of-line palletizer.
The system may also comprise a filter plug maker associated with the filter tip attachment, and a number of inline storage units located between the single machines of the system, serving to compensate any differences in operating speed between one machine and the next.
In manufacturing systems of the type in question, each machine needs to be re-supplied periodically with consumables and packaging materials, including tobacco filler, filter plugs, rolls of cigarette paper, metal foil paper and thermoplastic material, packet blanks, coupons, revenue stamps, and so forth. To this end, each machine is equipped with at least one sensor monitoring the depletion of the relative materials, as well as a counter positioned at the outfeed stage of the machine and serving to indicate the number of items turned out.
The demands of the market at the present time are such that individual brands tend to be manufactured in short runs. This means that there are frequent changeover operations, which impact negatively on the long-term productivity of manufacturing systems. With each changeover, in effect, the machines have to be shut down and emptied, and the various consumables replaced entirely or in part.
Conventionally, the task of renewing the supply of consumables to the various machines is carried out by production line operators, relying on an approximate and empirical approach and allowing generous margins of safety so as to ensure the scheduled production target can be reached comfortably, in readiness for changeover to another brand. This results in a measure of overproduction, compared to the original target, and/or the waste of a notable quantity of consumable materials already occupying the production line of the system, which cannot be used in the subsequent run to manufacture tobacco products of a different brand. The operation of removing large quantities of material from the production line and returning these same materials to stock possibly for subsequent use is one that requires a relatively long period of time to complete, and, besides the negative impact on the productivity of the system as already intimated, there is also the risk that the materials could be damaged during handling and transit.
The object of the present invention is to provide a method of managing a system for the manufacture of tobacco products, such as will be unaffected by the drawbacks mentioned above and, more particularly, effective in minimizing the waste of consumables, avoiding damage to consumable materials and limiting overproduction in respect of scheduled targets.
A further object of the invention is to provide a method of managing a system for the manufacture of tobacco products that will be easily implemented and can be run automatically by a monitoring, processing and control system using a limited number of sensing and computing operations.